st: Follow up on matrix building question -- correct version

Sorry My IE is diong strange things. Here is what I
meant to post:
With the help from the list I can now get to the
point where I have a matrix A that looks like this:
A[3,3]
coffee sugar wheat
coffee 0 1 0
sugar 1 0 1
wheat 1 0 0
I also have a time series data on coffee, sugar and
wheat. Now I would like to tell stata to cycle through
the variables and do the following:
for each variable I want to build a list of variables
to regress it on using the inputs from the matrix. So
if the cross element A["var", "var(i)] is == 1 then I
need to add var(i) to the list of things var is to be
regressed against.
I have a list of all the variables in a local variable
but not as a list it seems when I display it I get a
concatenated list of the names but I cannot address
them by names(1).
I wanted to do something like:
foreach var of varlist _all{
local reglist =""
if A[rownumb(`var', colnumb(`names'(`i'))] == 1 then
add names(`i') to reglist
}
Then I do my regression var on reglist
and onward to the next var...
How can I address the names in the local variable
names sequentially. It was built by:
levels namesvar, local(names) so holds all the
variable names that the matrix is using to name its
columns and rows. I am looking for some construct like
names(i) names[i] etc.
What is the best reference for me to read to learn
about this type of programming please. I just started
on building a fairly ambitious automated analysis tool
with stata and running into decent amount of
programming issues. I have Hamilton's book already but
it does not have much help on this type of question.
*
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